SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '609ecb57bec27c7346314101314d7ee78610aa5fb7ca9a0468dfcf28b9fc171b' 
  AND token = '0zFZ1qHB2TPOzjKB2GyqcZoB6/ijAzgQo6/YFUWdjEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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