SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd430366fd4e21492014a3c575782b53fbea5b70c1f70a0e59a299759bdd484da' 
  AND token = 'Udh52p8jeCxUVzCIHtBfUnz0ogi6VgIOje0c2W3uGNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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