SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '773ced7d0d81ffaea8cc44553949d142badea96aaa04c01217a701be1c7c0321' 
  AND token = 'WiUKRD2dSG9UTxIyYVniYDgeCzxHyrA44XKhVIBgpUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00100

JSON explain

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