SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7af609ce14946433616694597d7a89dcd4a876e182f9f6491b8a26b15f46024a' 
  AND token = 'hAb38XL3Ko4fPhADwn+EqlujavZaq55aV0Px75vOxmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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