SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d0b7ba72a8884ff1e47d32f49f99dc77857eaf6098be1e0da536a6a65bdd9f5' 
  AND token = '6z1FHLzwx7buB5pAsGscJjgM+VQkPCZYDyeWgj1PuBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}