SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a7b8c6dc79dd77a46c5466ed9d9983189e3d557be2291eb97dd26039903d465' 
  AND token = 'lnWR6Ch1VEPX4VqAkbdnmO8fM3583eTPE2PdFuhjvXA=' 
  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"
    }
  }
}