SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '97fe29990e41d2b2bb66bc3840fb7ac3e22deb3b7df51f79dfa44797358dab0f' 
  AND token = 'lXJJiOHC7MRlEZrIyotucuPDXTVLpAyRcqzGlg+pbJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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