SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5559ab47c3929da02f6ae4c3949eecffbcb4264c970d729e27f99344a80d097b' 
  AND token = 'ZbB3ftRf8fzat+++TwGe2mTezMHjLqMCPX+C/bZccaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}