SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '870fe3bf7bcd4138098665f4fd8f818c8f4288ace08495c3f27522b694bc940d' 
  AND token = 'y/DLQmKkogPlJCrqoH3OsTOkTOWriIFt+h0hOOdEtN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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