SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '865ea101c97de9ccfbe19fe0efd59ea1ad79ad7bcdc048aa5015cc4a58ec2228' 
  AND token = 't7UJD8J+DQRkQdue/rwYVnQqAck6tqEVNP/373WAPwM=' 
  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"
    }
  }
}