SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a6e720708592a1fb5fc8c3c36ab048240abaf81a9899a978f889362c43c8833' 
  AND token = 'z+aYbgvl7rA1QGdNC4Xu1L1bRLJlgnXN8+UJARKAgxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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