SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b16a637a6ce1b8ba26f41b968691539e206a2f63a5e9d1dcd086c95a56f6eadb' 
  AND token = 'aQQu4/gU6fInRhjx74mO1rR8Ku/GbRg55IIPsk9v8nA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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