SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de8841f6a34730e959a5b3b95da614a2fba6bd5825aaabb34165c1e4ab1c35cc' 
  AND token = 'v9VIp0i+B994/t6cAe6O9ykxvD0Q9PBfhiylBv6AXzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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