SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85853bdca93c9cf64aaf9a04a1d2ca6616d09bff891baaec778d3549d32e07d2' 
  AND token = 'F2ESg/uSz5+OHZclFHtcS/gB87sliMrM7PJ5nRHdMOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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