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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75bea278d0bfef76b6bd2e636e6f9169d3e9496fbd64a59ca527bdb3d9b0e01c' 
  AND token = 'Hu41txav9lTFOYldCmAwbNR+yWoNsfi3F4gqbY1D/vE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}