SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac0704a6a36155ea4d09d707eaca65acc35ebfef752c9286f22c5587d5cb3ed3' 
  AND token = 'qyJfAwL9iH3iBnD+OrBK0zZRhGoaOLSFzNHvl9ogsGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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