SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd23dcf6de06ef0947c59c2687367b95b8a39aacf81aba5a2aae736d9affdc8d7' 
  AND token = 'zK27iyeVDoUqaqxWvFPgWdtq04thSkP0F3gpdxaeVmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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