SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '830a48bdfa75bb4a6c3384eb77435c4e5b0a4bdbfcb3269b6f5d89a175ef7652' 
  AND token = 'Hc444v+houEWtlaNdz1AuFh6BnZ6UONwLGRLqNAHBAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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