SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2da215cb3158302d8387f4dd77810107a28667223a834811a365758567823751' 
  AND token = 'gfyAjpYEWB4ANwKlXXdFszb8/wEK/Ga+chibkOhvaX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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