SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0992d131bd72a7f0784ddd2c1e8225343132e20f5538faca91a19ff94caeef0d' 
  AND token = '6g6HqRHuzeXgultjKYj1M5YFJ6qMxAnfPwW6lxHTOvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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