SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '17b1053cd52f4682bd2f56bf2cb3a6927dd0147f3615c47cb469146fff8407e0' 
  AND token = 'jTcGXQiH2LZTgpdW7qnU8aYlSjX8KPH9ZDULP7lcYac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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