SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ef08fde2ee0cbc07bd4d80fad1b18686be45d2ef842148f56b75acddaa6e629' 
  AND token = 'RdsswCw8djZ5jPd4KOBPuNXu7nGsQyTxG1IB+vBrwws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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