Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de390a20c564428183441896422c725cbe15f3da0566e98579f90803db0fe69c' 
  AND token = 'VLSGLYQs1UQazHteA0jZGsfcVKLYfj6N8TIIXyHcb1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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