SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11b177e1bf702e2071d7720552d51731ccdd8c1bf9637da5f94cc39e79d40578' 
  AND token = 'iyEFth1cjrZOeht1ElEsqawwKb5KU/C042uOLXqFUe8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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