SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc1fa01bae367818b457d2016f110812d98ec4349084bc002c96977012a26f14' 
  AND token = '/314kSrIguJtvqODwmBX75LnjXoQvj5FoPkLjcgu1U0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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