SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f71557ed96a3b5b09f4d180714b52126c421099fa852453c6b7c655ce1d98e62' 
  AND token = 'n3QF9mybKQFGh3NkVa1D4o4BcEP/wg1dXyYYNjJ48pM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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