SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d79d8fc374d5b26c9b96085fe391348d14cdeff3663f9382c856bb88673b2c1' 
  AND token = 'MrBNQmaK+l7+P1CzgRTbI0g8Oz4VKzJwIHpX8tBgOs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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