SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a7d021d06e639451b771943f82cbeb5ed21788c14111bcff93d3cd08ccfc6156' 
  AND token = 'S4S/q7ZQFQEDPU7J8KhMq6Hr3ubKBQd/aZaHAmyG6sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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