SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8979b9ea3edcd2be4b9d240efa104b4a1d4d1859b59387d0d59100eeea7e6392' 
  AND token = 'D71YuettwSIPRyCdY6hIokyP/apxnUfESONJLQ4CQoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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