SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1be21ea53f3e4459327212fbdcb307f02e77dcf32cac6d4c0c3bcb31314b808' 
  AND token = 'NY3bExUhiaCSGClq9BRPi0nc7c6TwVa+zyTvsHA8p0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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