SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40a447fe068c5050882a162b41ba5ec028c00eff61f47a19895a36d91908370d' 
  AND token = 'Afpir6CW8tA4Jjqibt02FZlbHYy/ugdJ+ulumQccwKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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