SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63163cc0584032b5dfb4a3fea52a84913e1c5ff8a19871f8b7eb3f250dd7f2ed' 
  AND token = 'RMBzl7mnZMmtc3jkCDnyUfMCFGiFLg3/4+eK/WuBSNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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