SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fafc5bcd7bb2c9a2dcdc90bc9e82eb488b365a40f6525aafc5dbdf32e18ca89b' 
  AND token = 'OtAHIPwd3vGWdbaArpDc62eJsBK6lbGUyauwcgJrtQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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