SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66804a948d9c92ea72810583198f66479a3edb6d1b30d5ac23763f21c737381c' 
  AND token = 'wdYQDIo0mWrifYJyeDlzQOloSgYnV49Hr17oXyPlt2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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