SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '961020b324e47655ad3c0a5495a3979999ac35a3c7d65419ef27f014c563ef58' 
  AND token = 'FFMJxdvkdauiRXLa16h/tj7NceKgLqx4QgimuwHJNZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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