SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61eb50cf725d69ff5a08f6dd9508048594ff17b63072e5659c70397e51ce14e8' 
  AND token = 'qYLWS/jpKFYODfSYQxEP5bYsGRtBb/jd8c3Fw6NOKUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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