SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5572ff28611f0f5efd81963b02293ffe915a6f4f32e2cbfa3e41ac9e70385bbb' 
  AND token = '7n9bg9ggb743FdeTA+0k6u0qwmLnEBbY2vjTNWff6nE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}