SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1951cf7536a74f3c146450246ddb1490c42553e06843f7f662778d175270abdb' 
  AND token = 'bpX+C+lk48BhJdlrKbiPjbbLCeu5/hT/WSaylLHq7pk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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