SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '176ff2ff70c1ac05a3d8b69666653859c4f852d6a8abe66d3143a861bb9528ab' 
  AND token = 'FckBmX7S/UhITkKy7daiWxoKO2Vp9gSUbrDwnu0xk0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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