SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '079e739bdf0e34b62c63bcd0cd4724ddde3eba2ff0e64137910d1b2bf85cc264' 
  AND token = 'GP4feka7trXBc2POi/XICcUUxhVbuh7lJSvBGzbLvjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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