SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9433fc1b29c74bc9c90e2ae083fafbf85b24ac3cfaa14e57750239788203668' 
  AND token = 'ew9MYCE/tIXnsqShQGm7b5GfxMojsAAwkjLjINAtcOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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