SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8898b6f10780fb48481e82ab497eb60053f0dfb0c600fb8d79509bbd24f96a59' 
  AND token = 'M0OT+ZKjdsrQsUW/8ddcatjKhLb+E3iCIwIiO+2byTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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