SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17b53088cbfd9385dbce1cdf985a7883fcac8fe582674729b956245ff496f53e' 
  AND token = 'h9i/DDnrX9YtyScMneKd/WNIOdDjoLCVjjJYgssMW24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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