SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c0acd89bbcdcf30e92d12e6e63b90f019223f760a982765966ff60956010f38' 
  AND token = 'a97BcO5iY0SFRIUiu8ahRJ66uuoJdU+wZuudvZbce0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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