Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c81516b3bccfefa58337070093be606843e4361e8740d2edb9c5cd3fb7a23917' 
  AND token = 'F3++WMA97EeR4eoQxgVyJ2pInmVehr4l1gH6bmhCeQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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