SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcfaea9f7e4b7466e95105d997f1698aab77cdbf3f5b4b8425a7b36b40595ed2' 
  AND token = 'w9m8LTuLIC3+K1xhB6pAagzneqU/D+3DSpCyK+6/o34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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