SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd1bbdb4791aa58fe91a6c9ba6dbb8f75f54b8f9518e5193ede8c044527120308' 
  AND token = '3rylcoMW2pc3WNynroY57pjVGwqMZRY1yKmMlEJe2Kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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