SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34e13574e9ba9570685c0842a6893106075df33eb8ab1d5ca4c0a6d60d13d44e' 
  AND token = 'ZWnHlaNcLGEmN6B/Q0lnT2ePD8Hy0T6ATnzyI1ZjBf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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