SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56830fc97f20e550cdcaea3d16d21cd720020b927dd1f9b35afc2c19e596f5ee' 
  AND token = 'YhJoAgDA7T46HRz22XvXCpeRPGSV1LUeyOggVmo4VSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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