SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74fb52e7132007fcf720bdc076e58f1832f6f0edc0ccc8b8a56b22b64e1180d4' 
  AND token = '5twVcXTvHtBmUhJx752YbKBL9qZ5e6BpFw9CB2n24wU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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