SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e17800531f973a6f7cb972ee6397e845526e300923d15b6c892a90db0813346b' 
  AND token = 'b1VO9dZg8GrRGBFrkr89aIWagb0tovNn8OSHkZ+eSjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}