SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7c3fe0a68d2838c8827f756570005d55914a1363f9b614a17ce7e6402529b40b' 
  AND token = 'CHwWezfSUjCotINGG1UyBt2P/sWiD9Y959ADX/iZXcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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