SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd8e722b7e429832deda187ea20b2c12d4d9a6676d42efd71e514104d22cfd32c' 
  AND token = 'UG660ybzl+i5ItflJlwmRXbWnwhLscAp586vqDXZ36c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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