SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3c46ac392ccf227d0c742f01e24792db10aaed6f24f2206b12fb2af1db18b0c' 
  AND token = 'RfSSRxHMPExz0Ht6kRHz+mj3VtUhR2mc3+CpKwNUAgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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