SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd25a6b64d6acb86da665cc26755a71fae6df5c7570905dd63494ad1a089bc395' 
  AND token = 'uhTHjKsYCuNlblAWrwwuONZGhFc9bNgNMdUEzLTLVPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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