SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b28054f1adad2207bb8b03caf9d0e84b78e37a5406e8c27af29b9a2ec505697c' 
  AND token = '1nKXrn93gjK6PvC3fWVQUuxP+kFvwCyfRCFXaZrCnOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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