SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '028190bbe2c696a56c34f7803febd4ba567c1825ae74ef585a05dd15d1ed2c16' 
  AND token = 'GtEYBXpoCwZbOtpxZ/vLDpw9OzTx5NcHS+c/a1Wl1RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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