SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '357b75dd25340ec50ab73ba5aa3da96c737a294a5febfe13fca53b52fbf34060' 
  AND token = 'sGtQ2nW5ghpOqdXWri4sYYOWKEU42yXoaTjFr3wHKsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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