SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faa5d7eb80d1c4263452e62cb018b612605b34d273d0a5f4a1ad7f99e8568b7b' 
  AND token = 'TVgRkXBV6AwRxcMKKcMEYG+Vr3Ack3OlQUcot+NtcYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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