SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e275528b6614c7aaf602de59dfd2a572d222ae67d80ffe0ffb408fe5b715848e' 
  AND token = 'bW9qXAtfxGse7MAEYk9SCotxbf0RnzgE5v+wscxZnsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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