SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f380d0045a09fb9dc22e0929261c44857582eecfb2a8fffb195a9c8ebc4cbe7c' 
  AND token = 'D1oqAjn4hidrGXIt2TcExyW1KC4b9TjGQyP/UTeuiz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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