SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41e971146447a512b17092db14916317bd6d463902070d500cee71b0e420866d' 
  AND token = 'hTED4l0CvSbwZnuAefyhdbTYup9fhk6a/0m4zOypNmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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