SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e28867f51e98a0a1b49e74697a91b8b1ba608b69c7ac85f583ba59bec08f9390' 
  AND token = '1YFPwZHWbG7PmyTfzndEdvzTiQQH71shNzlHVZxhRhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}