SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4b85f21b35466bb8c5949f9a74bdb2159191a77fa6c51b0a93004d33736c8e71' 
  AND token = 'JtS7+lqbnyNJyLTEJUDD93aOOAqSNXs1xs3eKWr5ldI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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