SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bf05cb100f66c3ae01b27e603662e88059efde9d90244489fdc88b079fe25c2' 
  AND token = 'eoB6vG6jfBXDJg+powdUMYAJwf2LVc6+/O11Xwme2NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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