SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '41f5cc8c8a98d7dd8c3e53c0e2233930c03341b350ff30c5a88285066c027ece' 
  AND token = 'OqeKuAfzIiWebVvuk4ziRvHmBJknmA67Lk8ccNGOyns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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