SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60f27b3740a5cf9b3718acaf4cf285cb482ca03337de6fbbdfb6894193afd91f' 
  AND token = 'sjubCHhWN6pMCf/2WyKt7PXdYo4FPwehUXZ6qWYRJLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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