SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36372d8309e7d6bced466d0a73beb742ebe25dbe3c138bcce8b4d5ead6b463cc' 
  AND token = '4hW2HwBoCW6qAPJqO7K8wW7+m6fJ51ceqllqJ59ctjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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