SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5ad0e946335cf282635d7345df52d412934e8b599adf6c254e129f08e37c4b3' 
  AND token = 'hMCf+P/lRArMqrZGiYmyKeQow3GrjVhmEghokG9PYKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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