SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcf1b75de55816179e682b42c297847e96fdec5c168fd7a300fdc418563cae67' 
  AND token = 'DjuMfJxIT7dtvkATl4hCL/pYctfBPyxnX52hbj7euwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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