SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c717892aaa7ff621dc74b028beb95f571b34b51a0a4403080ea46379ed6d3f2d' 
  AND token = 'hi5gWBkhbzhEs73eJyChipb4I5ifv2UEFJM6QfqHwU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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