SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ef506df06d9c6162218a800f9fb416d3bf0affd1d356d665bd7412a59f0f6e9' 
  AND token = 'Ghhp0alKVYvoJUcwOiWo8aqk7Ugw+9W8p+HNbDTCeMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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