SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35c6ec71c0e534d683a40e0ccef3dc35f1fce1edf1de975f33fd4b5ee5ffd480' 
  AND token = 'lanQNDWcfyV9GSSqyoLfG7BlLWl0xg5NbKA53W9B2uQ=' 
  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"
    }
  }
}