SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc7cbb95e9ca9d470aca810882ab88facef009e24d8c03713bcfb0f9b88b0e8' 
  AND token = 'comoQvTKgVku89XBCVkXT12QvbimAdNUf5/A1vUSKnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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