SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b3795fbc3e60651def346c8e59bb0297768460c3af41b489a6034fcf3d32d0c' 
  AND token = 'wBQXxFq7ndPAZxz8ll3fD/tHPu/4Glep4uCa2gPpiYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}