SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce3096548efc3377ba46a623d736bd115165be410692faa76888f268061dd9d2' 
  AND token = '+p5zE6phViKFURHRVdIYp1X/EONEq7yjk5sYNPqzmgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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