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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '237ce409812a9ce3e3cda68dd2fc6c6a2b0d2e5c2ffdec5832c3a9c065b41b3c' 
  AND token = 'wRlLfCdloEOLdp3QB4wdbuJ0uyplMd9umambPCUMjJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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