SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e561b9d959f8ff2c64bc094632ef8211d4ee9cafd903181818437eb5db8174ba' 
  AND token = 'D/VU5FxglOImDp5NSyMhjet4QI8HlTmNsRtuvQfOJqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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