SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '116c688807e51840e6297e075530d415acd96303cb75dd65298144c604acdbb7' 
  AND token = 'Rqplbv8S4TIPZj2K5vtn8SYhaizQimFlCO0WUo/8BMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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