SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f69d45f579208cdf7847355bea69a6c24b750d8b44a1a72678c38b48373369' 
  AND token = '3F61PUa4jvYtJP7QK+S+0/S1EGlQytJ+6eldolhLz9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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