SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82ce7debe1356d6945ce09c9de53234bf604fc27fbafdd4e21344e93485f55a2' 
  AND token = 'iAzwTxYK0HSFGjwDegHu8LGcD3lIvBfvXGqfDVv8jBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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