SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22b3e51706ccd489270ee92fb4d322d55d431713335c1615dbd87c07845010f2' 
  AND token = 'jZ06fZlSEAfA/FnfeFy1I8hNI7o+WocK475xohdM+uI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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