SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11c5ffaec57b77699e49582b65252c0dd040b820116242602ac9f36fb32aba33' 
  AND token = '5jUFVx3ivF4fvlGhtI1bNlyVka6irZxzQ8hy65/Umvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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