SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4095c3c020d639fd05fef959b6b44b0d91545b3683577e68a8e435b1dc11ae1' 
  AND token = 'ZWxRDDJdWy31VgZs+DIsPfWqUj2OTK+Jq+9G+KbIIyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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