SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6a1ac4ad50ab367ed5cad39bec5db5901809b2aea0d31a4936dbd6193c3a1552' 
  AND token = 'wGa7GxxpM6unND47ie0FAodXaw+VVpSTnxMv6NjrddU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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