SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35736592ed036b16d6b81db31191d2ed55fb8d7758175af7cd7a652d8355ce6e' 
  AND token = 'zl1nJhjaAaURsxnbXOS0xwczjWmb2jIo2cXT4oRKHEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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