SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9407ae8e059d52f75be67de9e63c26b710d6cfb9a6097289d14fe56d279459a4' 
  AND token = 'IlAGFF8PYdBuAy0DFyz41TV0zkTsKfARLaKAuJQmW9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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