SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fec444d8fa27853b44deb3ba1c7d3cf21e883c9d3696b220f39afa5f3b69904b' 
  AND token = '3QGT2xV8Dp6EaMc++Xnvtp9z++UPdcPePxfTTQueHIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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