SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd56005fba6c6d6caac3ea7bb0f088a7560ad088698fb79979f213564f7068771' 
  AND token = 'AXynE35BfQmjDd0rJXUJYvtTK8oGrGeuzZ6sRIK//Q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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