SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '35c23fd2b548a4d6bb0329cefb2a1e28614ecd34a0402ae6157914f60fb608fb' 
  AND token = '3phvBISJZhF/hG408Yfp/5w3KhwRWJd1wnKOtojAsTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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