SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27fff398eb239fefeacb8f9d0d7bc30fe835d033ab79dbc908445462b7938627' 
  AND token = 'NpaR1Hr6weBQOmqmoBCkD5phNjcp23U5Pl6ilvxc+T8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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