SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c07a5e2baa4128639dd02015deeb955a64cb068de8d6febd2b20299035f80e8' 
  AND token = 'QviK6PSUKr7UZtvyH4CzLqwcmK69R2jaWI8xNMpQ3H0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}