SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13513a96d6b3bb51e9963ff61068d184004b54b349a82475c2440f2cf2b8f527' 
  AND token = 'oBNCJrChVY5oRNSWFYKPGuvyA2vnIvBkkvn8xBAlpS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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