SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f3a8fe241fa7bdedd08fac8262e70b19894d47d9dbe676e3d961fde82ec4683' 
  AND token = '1LszU028lL9vw4r6aZI1Ts2QetARCIg+xB7Pkk3xKgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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