SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9e451f275abe8713cdb6421c4352f2cf39e83c34c93f788b8a27c64527b9d6a' 
  AND token = '3PQd9oiJdJvaXmvnR1U1uKml6pyKeXwiuL+kqLS4EDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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