SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1e1c0542ce1c10df829a24bf6d8029d543390afb934eaca92af6455159574dd' 
  AND token = 'aVgyiwiAKT6zRRGLPwclBI4SXeWpo7JoSqrgYR+/51Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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