SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82d769a9880fa59b52e089533aee97aade915ceef8e0d4bfbae42660b9d623b8' 
  AND token = 'p658jxntx2xZEZuReV8WwKuyCPfozerf2Jm2hrjEfF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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