SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '38fe5919f7cf850d801c4f030622f1cfc945fa4b63d97fc69db62c730649a1a2' 
  AND token = 'vUgGmQzDH7AxOuiWVRcNBqF8O//ld4gZRmdGjU6fohA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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