SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1beb2bf72eff114e9cae139fff625990d22d494adc6a89d3f020d4bfce02e50' 
  AND token = 'Vco+SY+FsajVChiGeDP7ty999OEXxSuvvsF8jFn2V5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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