SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '588c942517d5e6995678ae876501c7e54b5c3bd0cacb80257bfced6da5853a83' 
  AND token = '8ySM10F1QKYpI/YgKjF31DJ22mmtAHq7+l/Zjy0/SVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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