SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57fd3a1053577178990cea0cdbf89e393f98bd62a1df12bdc129ff0fa28d64aa' 
  AND token = 'kqShKq9+PMwAl5isU+0pOXkZkI6rhucFzkfJFlkYEQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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