SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af4cc4129355fdb4403cc754f4bc1dafbd799268cb986dfbbeeb59dd4d60660d' 
  AND token = 'wcGDUGiK7+uahhzayGu70X4A5IFhKteLqum6+OzETiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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