SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8ba604b046886deb273ea80efe49683ec5bbeb67da5d64ca36558864812fb30' 
  AND token = 'bw1iZGM3HMPgUDFOtn1VWvCAwsdwdtO7MXPtAHvZ94c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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